1. Field of the Invention
The present invention relates to a method for switching a base station (BS), in particular, to a method for switching a BS according to the location of a mobile apparatus.
2. Description of Related Art
The wireless local area network (WLAN) is designed based on a cellular architecture. The WLAN contains a plurality of serving areas, i.e., cells. Each serving area is controlled by a base station (BS). In the cellular architecture, when a mobile apparatus moves from a serving area covered by a BS to a serving area covered by another BS, a server end apparatus monitors the signal intensity of the mobile apparatus, then automatically switches the mobile apparatus to another BS having a higher signal intensity, and automatically adapts the mobile apparatus to a suitable channel, so as to ensure the continuity of the communication of the mobile apparatus.
For example, FIG. 1 is a block diagram of a conventional wireless communication system. Referring to FIG. 1, it is assumed that a mobile apparatus intends to move from a point A to a point B. Here, the point A and the point B are located in a serving area 110 and a serving area 130, respectively. The serving area 110 and the serving area 130 are covered by a BS 120 and a BS 140, respectively.
It is assumed that the BS 120 provides services for the mobile apparatus. When a signal intensity of the BS 120 received by the mobile apparatus at the point A is higher than a switching threshold value, and a signal intensity of the BS 140 received by the mobile apparatus at the point B is lower than the switching threshold value, the server end apparatus will not switch the mobile apparatus to the BS 140, and the mobile apparatus is still served by the BS 120.
On the contrary, when the signal intensity of the BS 120 received by the mobile apparatus at the point A is lower than the switching threshold value, and the signal intensity of the BS 140 received by the mobile apparatus at the point B is higher than the switching threshold value, the server end apparatus switches the mobile apparatus to the BS 140.
However, if the switching threshold value is set too low, the switching may not occur even if the voltage of a neighboring BS is much higher than that of a current BS. Thus, the communication quality of the mobile apparatus is severely affected. Additionally, as the signal intensity is adopted to determine whether to switch a BS or not in the prior art, switching errors may easily occur.